Pregnant women and their partners can already peer at an unborn child’s chromosomes: with amniocentesis, they can learn about the presence or, more likely, absence of large-scale genetic defects, often gaining peace of mind. But only a small percentage of parents-to-be take the opportunity, because the procedure is invasive and uncomfortable—a large needle is inserted into the amniotic sac—and causes miscarriage in roughly one in 400 cases.

Researchers have long hoped to develop a noninvasive alternative. Ever since scientists discovered, in the 1990s, that pregnant women’s blood contains substantial amounts of fetal DNA, they’ve theorized that they could use this genetic material to test for fetal abnormalities like an extra copy of chromosome 21, which causes Down syndrome.

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Given that the risks of having blood drawn are minimal, the tests are likely to be widely used. While today fewer than 5 percent of pregnant women undergo amniocentesis, “I think we could see 50, 60, 70, 80 percent of American pregnancies getting genetic testing,” says Hank Greely, director of the Center for Law and the Biosciences at Stanford.

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But the moral quandaries are sure to intensify as well. If many more women receive information about genetic disorders like Down syndrome earlier in pregnancy, it’s likely that the number of abortions will rise. Inevitably, some people will object to the testing technology because of their opposition to abortion, says Greely. And some current parents of children with Down syndrome will worry that if fewer people are born with the disorder, medical research and public support will start to dry up. The unease deepens with less severe disorders like Kleinfelter’s syndrome, which is caused by an extra X chromosome in males. Boys with this syndrome often have few noticeable symptoms early on and may not be diagnosed until later in life, when they may experience atypical sexual development, learning difficulties, and infertility. If genetic testing identified more cases prenatally, some of those pregnancies would almost surely be terminated. Even firm supporters of abortion rights may find that thought troubling. Similarly, consider achondroplasia, which is an inherited form of dwarfism. If two parents with achondroplasia wanted a child who looked like them, “would it be wrong for them to terminate a normal-sized fetus?” Greely asks. “These are hard questions.”